Thermal responsive element



United States Patent THERMAL RESPONSIVE ELEMENT Samuel G. Eskin, Chicago, and Thomas B. Legeza, Westchester, Ill., assignors to The Dole Valve Company, Chicago, 11]., a corporation of Illinois Application August 20, 1954, Serial No. 451,185

' 3 Claims. (Cl. 73-358) This inventionrelates to improvements in thermal responsive elements and more particularly relates to such an element having means for amplifying the travel thereof incorporated as a part of the element.

A principal object of our invention is to provide a power type of thermostatic element in which the power member of the element is an expansible metal disk and which has a simple and efficient means for amplifying the travel of the disk for operating a device to be operated requiring afar greater travel than that of the disk.

Another object of our invention is to provide a thermal responsive element of the power type having a relatively small displacement upon increases in temperature, in which the displacement of the element is amplified by a novel and efficient arrangement of amplifying levers.

Another object and feature of the present invention is to provide an amplifying system for amplifying the travel of a power type of thermal responsive element in which amplifying levers react against a container for the element.

A further and more detailed object of our invention is to provide an amplifying system for a thermal responsive power element comprising a thin metal disk containing a thermally responsive fusible material within a casing and extending from the casing when the fusible material reaches its fusion point, in which an amplifying lever fulcrums about a container for the thermal responsive element, and is moved about its fulcrum point by expansion of the disk with respect to its casing and amplifies the travel of the disk.

Another object of our invention is to provide a simple form of integral thermal responsive element and housing therefor in which the power member of the thermal responsive element is a thin metallic disk contained within the housing and in which an amplifying lever arrangement is interposed between the disk and container for amplifying movement of the disk. 7

Still another object of our invention is to provide an amplifying means for operating a device having a relatively long range of travel from a thermal responsive element having a relatively short range of travel.

These and other objects of our invention will appear from time to time as the following specification proceeds and with reference to the accompanying drawings wherein:

Figure l is a transverse sectional view taken through a thermal responsive element and housing therefor in order to illustrate one form in which the thermal responsive element and amplifying systemof our invention may be embodied, and showing the thermal responsive element in a retracted position; and

Figure 2 is a plan view of the container and amplifying system shown in Figure l.

In the embodiment of our invention illustrated in the drawing, we have shown a housing, 50 threaded at one end thereof, as indicated by reference character 51, for threading within the tank (not shown) of a hot water heater or like device. The housing 50 is likewise shown as having an integrally formed hex, headed portion 52 at 2,873,608 Patented Feb. 17, 1959 the termination of the threads 51 affording a means for gripping the housing 50 by a wrench. At the inner end of the housing 50 is a casing 53 of a thermal responsive element 54, shown as being recessed within a shouldered or enlarged diameter portion 55 of the housing 50 and as being retained therein by spinning a reduced cross sectional area end wall 56 of the housing 56 inwardly into engagement with the side and bottom of the casing 53 of the thermal responsive element 54.

The casing 53 of the thermal responsive element 54 is shown as containing a fusible thermally expansible material 57, fusible in the operating range of the thermal responsive element for extending a disk 63 with respect to the casing 53 upon fusion of the fusible material. The end wall of the casing 53 is shown as being inclined downwardly from the inner margin thereof as indicated by reference character 60, and as being abutted by an annular seal 61 having an inclined under surface, the upper surface of which seal is pressed into engagement with the under surface of the flexible metal diaphragm 63 by the inwardly turned wall 56 of the housing 56. The outer side of the disk 63 is shown as abutting the shoulder of the portion 55 and as being maintained in abutting engagement therewith by said inwardly turned Wall 56.

It may be seen that in this form of our invention the thermal responsive element is sealed and retained in position in the housing 50 by the simple expedient of spinning the reduced cross sectional area wall 56 inwardly into engagement with the side wall and bottom of the casing 53.

The outer side of the disk 63 is shown as having a button or abutment member 65 welded or otherwise secured thereto and abutting the inner end of an adjustment screw 67, slotted at its outer end, as indicated by reference character 69, to afford a means for adjusting the position of a reaction lever 73.

The inner end of screw 67 is shown as having a rounded end having bearing engagement with the outer face of the button 65, to accommodate said screw to pivotally move about said button. A collar 71 is threaded on the screw 67. The collar 71 has a reaction lever 73 carried thereby and abutting a flange 74 at the upper end of said collar.

The reaction lever 73 is shown as having an arm 75 extending within a notch or recess 76 formed in the wall of the housing 50. The arm 75 abuts an inclined face 77 of said recess, inclined upwardly from the inner end of said recess at a relatively flat angle and fulcrums thereabout upon extension of the disk 63.

The opposite end of the reaction lever 73 from the arm 75 is shown as having an upright arm 79 having a reduced cross sectional area nib or-lug 83 projecting upwardly therefrom within a slot 554 formed in the amplifying lever 70. As herein shown, peaked shoulders 85, 85 are formed on opposite sides of the nib 83, the peaks of which come into bearing engagement with the amplifying lever 70, on opposite sides of the slot 84.

The inner end of the lever 70 is shown as extending within a notch 86 formed in the wall of the housing 50 on the opposite side thereof from the notch 76 and spaced therefrom toward the outer end of the housing 50. The notch 86 has an upper inclined face 87, inclined upwardly from the inner edge of the notch 86 at an opposite angle to the angle of inclination of the face 77of the notch 76, and abutted by the end of the amplifying lever, 70, when in its retracted position shown in Figure 1.

The opposite end of the amplifying lever 70 from the notch 86 is shown as having an arcuate downwardly extending guide prong 88 extending downwardly therefrom through a slot 89 formed in the reaction lever 73, for guiding the amplifying lever 70 during movement thereof and retaining said amplifying lever in an operative position in all positions of adjustment thereof. Inwardly of the prong 83 is an arcuate socket 90 opening toward the open end of the housing 50 and shown as having a rectangular aperture 91 leading therethrough for engagement with a device to 'be operated. The central portion of the amplifying lever 70 is open as indicated by reference character 92 to afford access to the adjusting screw 67 for adjusting the position of the collar 71 with respect to the diaphragm 63.

It may be seen from the foregoing that upon fusion of the fusible material 57 contained Within the casing 53 and extension of the flexible disk 63 therefrom, that the button 65 will react against the rounded end 66 of the adjusting screw 67 and move said adjusting screw outwardly, at the same time moving the reaction lever 73 about its fulcrum'point and exerting a force on the amplifying lever 78 through the knife edge shouldered portions thereof, to pivot said lever in an upward direction to the position indicated by dotted lines in Figure 1, and thus providing a double leverage amplifying system imparting a substantial movement to socket 90 of the amplifying lever 70 in contrast to movement of the diaphragm 63.

It may be seen from the foregoing that we have provided an extremely simple and eflicient amplifying system for thermal expansible elements, enabling the use of power type elements having short traveling flexible disks to operate devices requiring a relatively long range of travel, which not only takes advantage of the simplicity of the thermal responsive .element, but also enables a relatively inexpensive disk type element to be used and providing ample power for operating the device to be operated, with at least as great travel as the cylinder and piston types of power thermal responsive elements heretofore in use.

It may further be seen that the thermal responsive element and amplifying leverage system may be a unitary self contained'unit adapted to various uses and readily applied to the use for which it is adapted.

It will be understood that various modifications and variations of the present invention may be effected without departing from the spirit and scope of the novel concepts thereof.

We claim as our invention:

1. In a device of the class described, a housing, a thermostatic element contained within said housing comprising a casing containing a fusible thermally expansible material and a flexible metal disk within said housing and containing the thermally expansible material-within said casing, saidv housing having an inner wall having a notch formed therein and also having a diametrically opposed notch formed therein at a different level from said first notch, a reaction lever having engagement with said flexible disk adjacent the center'thereof, and having two arms, one forming a reaction arm and extending within and fulcrurning about said second notch and the other arm extending at right angles to said reaction arm at the opposite side of the'center of said reaction member from said reaction arm and having a central prong and bearing shoulders on opposite sides thereof, and an amplifying lever fulcruming about said first notchand carried on said prong and engaged by said bearing shoulders, andalso having an arcuate guide arm depending therefrom having guiding engagement with said reaction arm of said 'reactionlever, and having, a socket inwardly of said guide arm forming a connecting member for a device to be operated.

2. In combination with a thermal responsive element having a casing and a flexible metal disk containing a thermally expansible material within said casing, a housing for said thermal responsive element having an inner Wall having a first notch formed therein in spaced relation with respect to' said metal disk and forming a fulcrum point, said Wall having a second notch formed therein on the opposite side thereof from said first notch and form ing a second fulcrum point, an amplifying lever having rocking engagement with said first notch at one of its ends, a reaction lever having rocking engagement with said second notch at one of its ends and having an arm forming a mounting for said amplifying lever and reacting against said amplifying lever to pivot said lever about its point of engagement with said first notch, an operative connection from said flexible metal disk to said reaction lever intermediate the ends of said reaction lever, said amplifying lever having a guide arm extending therefrom toward said reaction lever, and said reaction lever having a slot therein forming a slidable guide for said guide arm.

3. In a device of the class described, a housing having an inner wall, a thermal responsive element contained within said housing and including a casing and a flexible metal disk closing an inner end of said casing and con-' taining a fusible thermally expansible material in said casing, an actuator button at the center of said disk, a stationary fulcrum abutment on said inner wall spaced axially from said disk and disposed adjacent the outer margin thereof, a reaction lever having engagement with said actuator button intermediate its ends and having an arm engageable with said stationary fulcrum abutment and moved about said fulcrum abutment upon extensible movement of said disk with respect to said casing, said reaction lever having a reaction arm extending oppositely from said first mentioned arm and having a bearing engaging surface thereon, another fulcrum abutment on said inner wall ofsaid housing in diametrically opposed relation with respect to said first mentioned fulcrum abutment and spaced axially outwardly along said wall from said disk and said first mentioned stationary fulcrum abut- 'ment, an amplifying lever having engagement with said second mentioned fulcrum abutment at one end, said bearing engaging surface of said reaction arm engaging the amplifying lever intermediate the ends of said amplifying lever, said amplifying lever having a guide arm slid ably engaging said first mentioned arm of said reaction lever and slidably guided thereby, and having means adjacent said guide arm forming a connecting means for a device to be operated.

References Cited in the file of this patent UNITED STATES PATENTS 

